Boxwood
Pros: Cheap, readily available, compact habit and small foliage, tolerant of heat, over/under water, and bad beginner decisions.
cons: stiff/brittle and prone to breaking if mishandled, Slow growing. You can wire new growth, but otherwise it is clip-and-grow which limits your options for learning a very important part of bonsai.
As others have said, cuttings and layering are intermediate and above horticulture topics and not a good place to start.
I know it may sound like a tired trope, but I would look at what grows well in your area, what strikes your eye, then intensively study the details of growing and styling that type of tree.
Focus on the horticulture with an eye for eventual styling (root care, tree health, maintaining branches for optional use later, that sort of thing), visit and study the full size trees that inspire you, and try to go to a bonsai show or two and make a study of how others are approaching the art.